RESUMEN
BACKGROUND AND OBJECTIVES: Pseudarthrosis is a complication after transforaminal lumbar interbody fusion (TLIF) that leads to recurrent symptoms and potential revision surgery. Subsidence of the interbody adds to the complexity of surgical revision. In addition, we report a novel technique for the treatment of TLIF pseudarthrosis with subsidence and propose an approach algorithm for TLIF cage removal. METHODS: Cases of reoperation for TLIF pseudarthrosis were reviewed. We report a novel technique using a bilateral prone transpsoas (PTP) approach to remove a subsided TLIF cage and place a new lateral cage. An approach algorithm was developed based on the experience of TLIF cage removal. The patient was placed in the prone position with somatosensory evoked potential and electromyography monitoring. A PTP retractor was placed using standard techniques on the ipsilateral side of the previous TLIF. After the discectomy, the subsided TLIF cage was visualized but unable to be removed. The initial dilator was closed, and a second PTP retractor was placed on the contralateral side. After annulotomy and discectomy to circumferentially isolate the subsided cage, a box cutter was used to push and mobilize the TLIF cage from this contralateral side, which could then be pulled out from the ipsilateral side. A standard lateral interbody cage was then placed. RESULTS: Retractor time was less than 10 minutes on each side. The patient's symptoms resolved postoperatively. We review illustrative cases of various approaches for TLIF cage removal spanning the lumbosacral spine and recommend an operative approach based on the lumbar level, degree of subsidence, and mobility of the interbody. CONCLUSION: Bilateral PTP retractors for TLIF cage removal may be effectively used in cases of pseudarthrosis with severe cage subsidence. Careful consideration of various factors, including patient surgical history, body habitus, and intraoperative findings, is essential in determining the appropriate treatment for these complex cases.
RESUMEN
Anterior cervical discectomy and fusion (ACDF) is a common neurosurgical procedure. Portions of the procedure, such as the discectomy, foraminotomy, graft placement, and plate placement, are often performed using operating microscopes to maximize visualization and minimize neurovascular injury. Although standard operating microscopes offer superb visualization, they lack ergonomic and educational utility. With modern advancements in digital imaging and stereopsis, there has been a surge of interest in evaluating modern exoscopes for their utility in cranial and spinal neurosurgery.1-3 In Video 1, we demonstrate the use of a commercial three-dimensional exoscope from skin incision through completion of a two-level ACDF. Both the lead surgeon and the assistant surgeon were able to maintain a neutral, ergonomic, and comfortable position throughout the surgery. Furthermore, we tested the utility of this technique in 15 patients undergoing ACDF (2 one-level, 9 two-level, 3 three-level, and 1 four-level). Mean (SD) overall operative time was 118 (34) minutes (2-level ACDF, 110 [12] minutes), and mean (SD) blood loss was 23 (8.0) mL. The Neck Disability Index score and visual analog scale score for neck pain improved significantly at 6 weeks postoperatively (from 59.6 [1.3] to 27.9 [3.0] and from 6.3 [1.0] to 2.5 [0.92], respectively; P < 0.001 for both). Thus, excellent clinical outcomes can be achieved using three-dimensional exoscopes with comparable operative time and blood loss compared with conventional surgical microscopes or loupes. Given the improved ergonomic and teaching potential of exoscopes, the use of three-dimensional exoscopes for neurosurgical and spine surgeries warrants further investigation.